Aqueous solutions Flashcards
The solubility of substances in aqueous biological solutions is crucial in which 3 processes?
Transport of gases
Transport of inorganic materials
Application and transport of drugs
Property that all atoms have to do with how much that atom wants to pull electrons towards itself away from other atoms that are attatched to it in the molecule
Electronegativity
When oxygen and hydrogen bonds have different electronegativities this is called what?
Polarbonds
A bond that has a delta positive and a delta negative end
Polar bond
A bond that doesn’t have partial changes due to the 2 atoms in the bond not having different electronegativities
Non polar bond
The most electronegative element in the periodic table
Fluorine
The water molecule is described as
Bent
Type of dipole-dipole interaction that you only get when you have polar bonds that contain OH, NH, or FH
Hydrogen bonding
Which 3 things does there need to be to get hydrogen bonding?
OH, FH, NH
Hydrogen bonding has important impacts on the …… of the molecule
Properties
The stronger the interactions between the molecules, the …… the boiling point will be because the ….. it will be to pull those molecules apart from each other
Higher
Harder
What gives a molecule a higher boiling point?
Strong interactions
Simplest molecule to exist that is liquid at room temp and atmospheric pressure
Water
Simplest molecule that could be the solvent for a biological system to evolve in
Water
Molecules are always moving around, hydrogen bonds are fixed and broken and are always moving around and never fixed in pairs
Liquid water
Molecules stop moving, hydrogen bonding is fixed between pairs of molecules
Solid
Why is solid water less dense than liquid water?
Because the molecules are further apart, and there is more space in between them
At which degrees celcius does water maximum density occur?
4
The freezing point of water ….. as pressure increases
Decreases
Substances that give ions when dissolved
Electrolytes
Explain how water is a solvent to sodium chloride
Water comes in and takes a chloride and surrounds it with water molecules and surrounds the negatively charged an ion with water molecules, so the postively charged end of the water molecules are closest to the negative charge on the an ion
Why are some salts more difficult to dissolve in water than other?
Some dont mind being surrounded by water molecules, but some prefer to stay in the solid with their other cat ions and an ions
Hydration spheres
Spheres of water molecules that surround the cations and the anions
Explain why solubility is much less for gases eg oxygen than polar things
These interactions are much more weaker as we are having to induce a dipole in the O2 molecule rather than it being there all the time
Formed when 1 or more chemical species dissolve in a liquid
Solution
Substance that dissolves in a liquid. Can be solid, liquid or gas
Solute
Liquid in which the solute dissolves
Solvent
Dissolves to give ions in solution
Electrolyte
Dissolves without the formation of ions
Non electrolyte
When the amount of solute is much less than the amount of the solvent
Dilute solution
When a solid dissolves, and the only thing you get in. the solution is cations and anions, its means it is a…..
Strong electrolyte
When you put it in water, it can dissolve to give cations and anions but it doesnt have to
Weak electrolyte
Explain why acetic acid isnt a strong electrolyte
Because most of the acetic acid molecules dissolve in water, and only some of them go onto give cations and anions, so therefore the dissolving process does not exclusively give cations and anions
Water is a good solvent for many compounds because of its…
Polar nature
Explain how OH bonds are polar
Due to the O being much more electronegative than the H, giving the O a partial negative charge and the H a partial positive charge
When a polar molecule dissolves, what interaction drives the process?
A dipole-dipole interaction
When a gas dissolves in water, what interaction drives this process?
Dipole-induced interactions
A solid that dissolves in water to give ions
Electrolyte
A strong electrolyte is one which…
Completely dissolves
A weak electrolyte is one which…
Partially dissolves, giving an equilibrium between undissolved solid and dissolved ions
